响应曲面法优化假单胞菌LKY-5对二苯并噻吩的降解

In this research, the degradation of dibenzothiophene （DBT） was investigated by using Pseudomonas sp. LKY-5isolated from oil contaminated soil. The response surface methodology （RSM） based on the Box-Behnken design （BBD）was applied for evaluating the interactive effects of four independent variables including substrate concentration, temperature,pH and agitation rate on the DBT removal response. A total of 29 experiments for four factors at three levels wereconducted in present study. A second-order regression model was then developed, and the analysis of variance （ANOVA）illustrated that the proposed quadratic model could be utilized to navigate the design space. The value of determination coefficient（R2=0.953 4） indicated a satisfactory agreement between the quadratic model and the experimental data. It was found thatDBT removal was more significantly affected （P〈0.000 1） by substrate concentration compared with other three parameters.An 100% degradation of DBT could be obtained by Pseudomonas sp. LKY-5 at a substrate concentration of 100 mg/L.     

响应面法优化采油用蜡状芽孢杆菌发酵配方

为了提高采油用蜡状芽孢杆菌(km121)发酵液的活菌数,采用响应面法对发酵培养基进行优化。首先利用Plackett-Burman设计筛选出培养基中影响活菌数的显著因子;然后通过爬坡实验找到显著因子对应的最大响应值区域,最后利用响应面法的Box-Behnken中心组合实验确定各显著因子的最佳比例[1],优化后的培养基组分为:葡萄糖22.7 g/L,尿素1.1 g/L,硫酸铵1 g/L,硫酸镁1 g/L,磷酸二氢钠2.5 g/L,磷酸氢二钾0.5 g/L,酵母膏1.5 g/L,氯化钙0.02 g/L,在此条件下实际实验值为51.2×10^8cfu/mL,活菌数比优化前的33.2×10^8cfu/mL提高了35.2%。     

响应曲面法优化超重力-络合铁净化石油伴生气中的H2S

以超重力旋转填料床为脱硫设备,采用络合铁溶液对石油伴生气中的H2S进行净化研究。采用响应曲面法建立脱硫率与铁离子浓度、液气比、超重力因子之间的BBD模型,研究结果表明该法可有效地优化脱硫效果。在铁离子浓度为0.16mil/L,液气比为20.67L/m3,超重力因子为87时,针对H2S浓度为7g/m3的石油伴生气脱硫率可达98.81%。采用XRD和SEM对产物硫磺进行表征,研究结果证明硫磺颗粒大、易团聚,有利于固液分离。     

Poly (3-Hydroxybutyrate) Production from Crude Oil by Haloarcula sp. IRU1: Optimization of Culture Conditions by Taguchi Method

Abstract

Petroleum contamination is a widespread and well-recognized global environmental threat to human health and ecosystems. Haloarcula sp. IRU1 was cultivated axenically in synthetic liquid media with crude oil as sole carbon and energy source. After 5 days' incubation, cell dry weight (CDW) and poly (3-hydroxybutyrate) (PHB) production were studied by conventional methods. The optimized conditions for the maximum production of PHB were temperature 47°C, crude oil 2%, yeast extract 0.4%, and NaH₂PO₄, 0.016% as carbon, nitrogen, and phosphorus sources, respectively. In conclusion, Haloarcula sp. IRU1 can biodegrade crude oil and use it as a carbon source for PHB production.